In-situ formation of non-volatile lanthanide thin film precursors and use in ALD and CVD

Abstract

Methods of forming a lanthanide-containing film comprising exposing a substrate surface to a lanthanide-containing precursor, a metal halide and a nitrogen precursor are described. The lanthanide-containing precursor has the general formula (CpRx)2Ln(N,N-dialkylamidinate) where Cp is a cyclopentadienyl or 6, 7 or 8 membered ring, R is H, C1-C4 alkyl, x=1 to number of C in Cp, alkyl is C1 to C4 alkyl. The metal halide deposits metal halide on the substrate surface and reacts with lanthanide-containing species to convert the lanthanide-containing species to a lanthanide halide. The nitrogen-containing precursor forms a lanthanide-metal-nitride film on the substrate surface.

What is claimed is: 
     
       1. A method of forming a lanthanide-containing film, the method comprising:
 exposing a substrate surface to a lanthanide-containing precursor to form a lanthanide-containing species on the substrate surface, the lanthanide-containing precursor having the general formula (CpR x ) 2 Ln(N,N-dialkylamidinate) where Cp is a cyclopentadienyl or 6, 7 or 8 membered ring, R is H, C1-C4 alkyl, x=1 to number of C in Cp, alkyl is C1 to C4 alkyl; 
 exposing the substrate surface to a metal halide to deposit metal halide on the substrate surface and react with lanthanide-containing species to convert the lanthanide-containing species to a lanthanide halide; and 
 exposing the lanthanide halide and metal halide to a nitrogen-containing precursor to form a lanthanide-metal-nitride film on the substrate surface. 
 
     
     
       2. The method of  claim 1 , wherein at least one of the R groups is a C1-C4 alkyl groups. 
     
     
       3. The method of  claim 1 , wherein Cp is a cyclopentadienyl group having at least one R group comprising an alkyl group having 2 to 4 carbon atoms. 
     
     
       4. The method of  claim 1 , wherein the lanthanide is selected from the group consisting of La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Y, Sc and combinations thereof. 
     
     
       5. The method of  claim 4 , wherein the metal atom comprises La. 
     
     
       6. The method of  claim 1 , wherein the metal halide comprises titanium. 
     
     
       7. The method of  claim 6 , wherein the metal halide comprises TiCl x B y I lz , where the sum of x, y and z is 4. 
     
     
       8. The method of  claim 7 , wherein the metal halide consists essentially of TiCl 4 . 
     
     
       9. The method of  claim 1 , wherein the nitrogen-containing precursor comprises one or more of N 2 , NH 3 , hydrazine, hydrazine derivatives, NO 2 , plasmas thereof or combinations thereof. 
     
     
       10. The method of  claim 1 , wherein the method occurs at a temperature in the range of about 200 to about 300 C. 
     
     
       11. A method of forming a lanthanide-containing film, the method comprising:
 exposing a substrate surface to a lanthanide-containing precursor to form a lanthanide-containing species on the substrate surface, the lanthanide-containing precursor having the general formula (CpR x ) 2 Ln(N,N-dialkylamidinate) where Cp is cyclopentadienyl, ring or (ChxR x ) 2 Ln(N,N-dialkylamidinate), where Chx is a cyclohexadienyl ring, or (ChpR x ) 2 Ln(N,N-dialkylamidinate), where Chp is a cycloheptadienyl ring or (CocR x ) 2 Ln(N,N-dialkylamidinate), where Coc is a cyclooctadienyl each R is H, C1-C4 alkyl, x=1 to number of C in the cyclodialkenyl ring, alkyl is C1 to C4 alkyl, with the proviso that at least one R is not H; 
 exposing the substrate surface to a titanium halide to deposit titanium halide on the substrate surface and react with the lanthanide-containing species to convert the lanthanide-containing species to a lanthanide halide; and 
 exposing the lanthanide halide and titanium halide to a nitrogen-containing precursor to form a lanthanide-titanium-nitride film on the substrate surface. 
 
     
     
       12. The method of  claim 11 , wherein Cp is a cyclopentadienyl group having at least one R group comprising an alkyl group having 2 to 4 carbon atoms. 
     
     
       13. The method of  claim 11 , wherein the lanthanide is selected from the group consisting of La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Y, Sc and combinations thereof. 
     
     
       14. The method of  claim 13 , wherein the metal atom comprises La. 
     
     
       15. The method of  claim 11 , wherein the titanium halide comprises TiCl x B y I lz , where the sum of x, y and z is 4. 
     
     
       16. The method of  claim 11 , wherein the nitrogen-containing precursor comprises one or more of N 2 , NH 3 , hydrazine, hydrazine derivatives, NO 2 , plasmas thereof or combinations thereof. 
     
     
       17. A method of forming a lanthanide-containing film, the method comprising:
 exposing a substrate surface to a lanthanide-containing precursor to form a lanthanide-containing species on the substrate surface, the lanthanide-containing precursor having the general formula (CpR x ) 2 Ln(N,N-dialkylamidinate) where Cp is a cyclopentadienyl ring, R is H, C1-C4 alkyl, x=1 to 5, alkyl is C1 to C4 alkyl; 
 exposing the lanthanide containing species on the substrate surface to HF or HF-pyridine to form a lanthanide-fluoride film on the substrate surface. 
 
     
     
       18. The method of  claim 17 , wherein the lanthanide is selected from the group consisting of La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Y, Sc and combinations thereof. 
     
     
       19. The method of  claim 18 , wherein the metal atom comprises La. 
     
     
       20. The method of  claim 17 , wherein the method occurs at a temperature in the range of about 200 to about 300 C.